The present invention relates to a heat exchanger for use as condenser in radiators and car coolers.
It is known in the art to construct a heat exchanger with a core and headers, the core including flat tubes stacked one above another and fins sandwiched between the tubes.
In constructing such heat exchangers, the tubes and fins are assembled into the core, and then the core and the headers are provisionally connected to each other by driving the tube ends into the headers by power such as a pneumatic cylinder or by manual force such as by a hammer. Finally the permanent joint is effected by brazing or any other means among the tubes, fins and headers.
Under this method it is difficult to determine the optimum lengths of the tubes to be inserted in the headers. If the inserted portion of the tube is too short the joint between the headers and the tubes becomes too weak to withstand a long period of use. If the inserted portion is too long, a brazing substance is likely to intrude into the headers, thereby causing a choking problem. To avoid such improper joints between the headers and the tubes, it is necessary to check if the tube ends are adequately inserted into the headers when the headers and the tubes are provisionally assembled. If it is found that the insertion is excessive or short, a correction is necessary. The correction consumes labor and time. In addition, even if the correction is made, the tubes or the headers are likely to dislocate before the permanent brazing is carried out, another correction becomes necessary.
Accordingly, it is an object of the present invention to provide a heat exchanger capable of easy fabrication with the adequate insertion of the tubes in the headers.
Other objects and advantages of the present invention will become more apparent from the following detailed description, when taken in conjunction with the accompanying drawings which show, for the purpose of illustration only, one embodiment in accordance with the present invention.